I think that design docs for games are a great source of knowledge about the art/science of game design.
In this topic I want to collect the freely available design docs from finished games, so other can see how where those games started.
Feel free to add your finds - I will occasional edit this first post to include any of your "new finds" and the docs I will stumble upon.
Without further ado, links to game design docs in alphabetical order:
Play with Fire